Telefonaktiebolaget Lm Ericsson (publ)

The Royal Institution for the Advancement of Learning/mcgill University

Scuola Superiore Santanna

Isabella Cerutti

Piero Castoldi

Nicola Andriolli

Odile Liboiron-Ladouceur

Antonella Bogoni

Filippo Cugini

Nicola Sambo

Mirco Scaffardi

Pier Giorgio Raponi

Md Shafiqul Hai

Luca Valcarenghi

Alessio Giorgetti

Philippe Velha

An optical switch () comprising: inputs () to receive input optical signals at respective wavelengths and having planar wavefronts; conversion apparatus () to convert each input optical signal into a respective optical signal having a respective helical wavefront, each helical wavefront having a different orbital angular momentum, OAM; optical multiplexing apparatus () to receive each helical wavefront optical signal from the conversion apparatus and to multiplex the helical wavefront optical signals into an OAM multiplexed optical signal; and optical demultiplexing apparatus () comprising a plurality of outputs (), the optical demultiplexing apparatus arranged to: receive the OAM multiplexed optical signal; demultiplex the OAM multiplexed optical signal into a plurality of wavelength multiplexed optical signals each having a different OAM; reconvert each wavelength multiplexed optical signal from its helical wavefront into a respective planar wavefront; and deliver each planar wavefront wavelength multiplexed optical signal to a respective one of the outputs according to the respective OAM it had before reconversion.

Optical switching

Optical solutions to address and overcome the issues of superseding/replacing electrical interconnection networks have generally exploited some form of optical space switching. Such optical space switching architectures required multiple switching elements, leading to increased power consumption and footprint issues. Accordingly, it would be beneficial for new optical, e.g. fiber optic or integrated optical, interconnection architectures to address the traditional hierarchal time-division multiplexed (TDM) space based routing and interconnection to provide reduced latency, increased flexibility, lower cost, and lower power consumption. Accordingly, it would be beneficial to exploit networks operating in multiple domains by overlaying mode division multiplexing to provide increased throughput in bus, point-to-point networks, and multi-cast networks, for example, discretely or in combination with wavelength division multiplexing.

Optical interconnection methods and systems exploiting mode multiplexing

Scalability and energy efficiency are key issues in data centers imposing tight constraints on the networking infrastructure connecting the servers. Optical interconnection mitigates electronic limitations but the additional flexibility offered by WDM and datarate across a data center interconnection network requires architectural design, photonic technologies, and operating strategies be selected and optimized to meet power consumption requirements. Multi-plane architectures based upon space-wavelength domain architectures have been proposed to overcome scalability limitations. It would be beneficial to extend space and time switching domains with the wavelength domain for additional capacity to increase throughput as well as providing same electro-optic interface. Accordingly, the inventors have established space-time domain interconnection network architectures with wavelength domain overlay overcoming power consumption issues, especially at low utilization, by exploiting all-optical implementations with active elements which act simultaneously as a switch and an amplifier, and the possibility to remain in an idle state when unused.

Methods and devices for space-time multi-plane optical networks

A method of restoration for an optical network, the network comprising a plurality of nodes () interconnected with each other by optical links (), a subset of the nodes () each comprising a regenerator, the method comprising: storing) a quality of transmission parameter and a regenerator availability at each of the plurality of nodes (); notifying () a branch node () in response to detecting a failure () within a link () forming part of the path between a source node () and a destination node (), wherein the branch node () is the neighbouring upstream node () upstream of the link failure (), the branch node () having a regenerator; the branch node () computing () a restoration segment () to a merge node () having a regenerator which is a neighbouring downstream node which is downstream of the link failure (), the restoration path () being based on the quality of transmission parameter and regenerator availability information; restoring () the path between the source node () and the destination node () using the restoration segment ().

Restoration scheme for an optical network and method of using such a scheme

Growing community of inventors

Pisa, Italy

Isabella Cerutti